Proposal of using a time constant for specifying atrium smoke filling in fire codes

Wan Ki Chow, J. Li

Research output: Journal article publicationJournal articleAcademic research


A time constant including building geometry and design fire characteristics was suggested for specifying smoke filling in atria. From the survey results on 138 local atria, time constants of 73 atria were calculated. The smoke filling times required to fill 80 % of the space volume were evaluated from the NFPA smoke filling equation with a slow t2-fire. The time for the smoke front to reach the ceiling was taken into account. It is further confirmed that time constant is a better parameter than the space volume used in the current fire codes, and is thus recommended to the Authority.
Original languageEnglish
Pages (from-to)58-60
Number of pages3
JournalInternational journal on engineering performance-based fire codes
Issue number2
Publication statusPublished - 2000

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